What we know about the Hamas assault on Israel

This is what we know about the conflict so far:

How it unfolded

One thousand Hamas militants attacked Israel from around 6:30 am (0330 GMT) on Saturday, the Jewish holiday of Simchat Torah, in an assault that came 50 years after the outbreak of the 1973 Arab-Israeli war.

The Islamists fired thousands of rockets into Israel and used explosives and bulldozers to break through the fence around the blockaded Palestinian enclave.

Using motorbikes, pickup trucks, motorised gliders and speed boats, the militants streamed into Israel, including the cities of Ashkelon, Ofakim and Sderot.

The gunmen carried out a bloody attack on a music festival attended by hundreds of young Israelis and foreigners near Kibbutz Reim, close to Gaza.

Israel said Hamas took more than 100 hostages. They include an unknown number of foreigners, among them Americans.

How Israel is responding

Israel officially declared war on Hamas on Sunday.

Prime Minister Benjamin Netanyahu vowed to reduce to "rubble" the group's hideouts in Gaza, an impoverished enclave of 2.3 million people hemmed in by an Israeli blockade for more than 15 years.

He warned Gaza civilians to move away from Hamas sites as Israel's army said it carried out air strikes on its positions in an operation dubbed "Swords of Iron".

On Monday the army declared its forces were now "in control" of southern communities attacked by Hamas.

The army said Monday it struck 500 Hamas and Islamic Jihad sites overnight, after carrying out 800 previously.

Hamas' armed wing, the Ezzedine al-Qassam Brigades, said Monday that Israeli air strikes had killed "four of the enemy's prisoners" overnight. AFP was unable to immediately verify the claim.

The Israeli military has massed tens of thousands of troops and heavy armour near Gaza, with Palestinians bracing for a potential ground assault.

Defence Minister Yoav Gallant on Monday ordered a "complete siege" on Gaza, meaning "no electricity, no food, no water, no gas".

More than 1,200 killed

Israel says Hamas gunmen have killed more than 700 people and wounded over 2,000 in Israeli cities, towns and kibbutz communities.

AFP journalists saw the bullet-riddled bodies of civilians on the streets in at least three locations in Israel: Sderot, the nearby kibbutz of Gevim and Zikim beach north of the Palestinian enclave.

An estimated 250 people were killed at the Supernova music festival near Kibbutz Reim, a volunteer who helped recover the bodies told AFP.

On the Gaza side, health officials said at least 560 people had been killed and more than 2,900 wounded, taking the combined toll to at least 1,260 dead.

The United States said at least nine Americans were killed, with more citizens unaccounted for. A Briton, 12 Thais and 10 Nepalis, and at least eight French nationals are among other foreigners killed.

What Hamas says about the offensive

Hamas said it fired 5,000 rockets in an offensive it has branded "Operation Al-Aqsa Flood".

Its chief Ismail Haniyeh on Saturday vowed to press ahead with "the battle to liberate our land and our prisoners languishing in occupation prisons".

Hamas has called on "resistance fighters in the West Bank" as well as in "Arab and Islamic nations" to join the battle.

It on Monday ruled out negotiating a prisoner swap with Israel as "the military operation is still ongoing".

What allies are doing

Lebanon's Iran-backed Shiite militant group Hezbollah said it launched missiles and artillery shells into northern Israel early Sunday "in solidarity" with the Hamas offensive.

The Israeli army said it retaliated with artillery fire.

On Monday, Israel's army said it killed a number of armed suspects who crossed the border from Lebanon and that its helicopters carried out strikes in the frontier area.

In Egypt on Sunday, a policeman opened fire on an Israeli tour group in the northern city of Alexandria, killing two Israelis and their Egyptian guide.

The United States has vowed "rock solid and unwavering" support for Israel, with President Joe Biden on Sunday ordering "additional support" for its key ally and moving an aircraft carrier group to the eastern Mediterranean.

Iran on Monday rejected allegations it had a role in Hamas' attack, after the Wall Street Journal reported that it had helped to plan it and gave the Palestinian group the "green light" for the assault.

How the world has reacted

United Nations Secretary-General Antonio Guterres condemned "in the strongest terms" Hamas' attack on Israel and called for "diplomatic efforts to avoid a wider conflagration".

Western capitals, many of whom have designated Hamas a "terrorist" organisation, also condemned the Islamist group's assault.

The European Union on Monday said it was halting development aid payments to Palestinians.

Russia on Monday said creating a Palestinian state was the "most reliable" solution for peace in Israel and that fighting terrorism alone would not ensure security.

Turkish President Recep Tayyip Erdogan, who strongly supports the Palestinian cause, urged both sides "to support peace".